Clinical bovine paratuberculosis - first report in the state of Pará

ABSTRACT The objective of this work was to describe the clinical, pathological, and serological aspects of paratuberculosis in a bullock on dairy and beef farm in the municipality of Inhangapí, state of Pará. The animal was raised extensively and presented progressive weight loss, pale mucous membranes, and chronic diarrhea. A blood sample was collected for serology by the indirect ELISA technique. Due to the unfavorable prognosis, the animal was euthanized and necropsied. At necropsy, there was thickened and wrinkled intestinal mucosa, enlarged mesenteric lymph nodes and liquid intestinal contents with a brown color. Organ fragments were fixed in 10% buffered formaldehyde, embedded in paraffin wax, cut, and stained by hematoxylin and eosin and by Ziehl-Neelsen techniques. Histopathology showed intense granulomatous infiltration with Langhans giant cells in the lamina propria and submucosa of the small intestine, Peyer patches and mesenteric lymph nodes. Ziehl-Neelsen staining revealed many intralesional acid-fast bacilli. Antibody searching against Mycobacterium avium (subsp.) paratuberculosis was positive. The diagnosis of paratuberculosis was based on epidemiological, clinical, pathological, and serological data. This is the first report of clinical paratuberculosis, confirmed by pathology and serology, in a bullock in the state of Pará.